One Last Rival
by wavesorcerer14
Summary: Ayano Aishi was willing to do anything to steal her senpai's heart. Unmerciful, she killed, tortured, and ruined each one of her rivals' lives. However, what actually happens when Senpai finally accepts her feelings towards him? Not to mention, what secrets have Senpai been hiding from her?
1. Senpais & Sisters

**CHAPTER ONE: Senpais & Sisters**

* * *

 _ **A/N: I hope that you enjoy this story! Feel free to review and note that I don't mind suggestions. In fact, please give me suggestions because I've been having writer's block lately!**_ ** _Anyways, here goes the first chapter of One Last Rival! -wavesorcerer14_**

* * *

My shadow was covered by the dark milieu of midnight. My senpai had previously roamed the plaza of Buzara Town for a while and was now walking back home. I slid across the nearest wall, eying my senpai with great attention. Suddenly, he stopped walking. Holding my breath, I tried to squeeze myself against the wall and froze. Silence. I was hidden by the shadows of Akademi High's gates.

"I know you're there, Ayano," Senpai calmly said and turned around, revealing his dreamy black eyes. My heart started pounding.

"Uh… Uh… I- I… Was…" I started, but passed out due to my anxiety.

* * *

I woke up feeling sore. _Where am I?_ I wondered, noticing the ropes restraining me from moving my arms and legs.

"Oh, I see that you're up, Ayano. Perfect." Senpai chuckled.

"W- What are you doing?!" I frantically cried, discovering a new emotion. Fear.

"I've been watching you, Ayano," Senpai started. "Don't think that I haven't seen your shadow lying on the ground, or your ponytail slip around corners, or your reflection staring at me in mirrors you haven't noticed. You are a peculiar girl, Ayano. I can tell that all of your "warm smiles" and "compliments" are fake. Should I even get started on Kokona-Chan and Saki-Chan's deaths?" My heart immediately started thrashing around. "I've been watching you. I know better than to just let a creep like you stalk me. In return, I've been following you back in return. I saw what you did to Saki-Chan in your basement. Her screams and looks of horror still haunt me to this day. I know you broke her. Kokona-Chan and Saki-Chan were two of my few friends. Do you really think that I can forgive you for that? What do you have to say to that, Ayano?" He finished and stared at me, his now cold, black eyes piercing into my heart.

"I- I'm sorry, Senpai!" I wailed, bursting into tears. Clearly this was not the reaction Senpai had expected, as his mouth opened in shock. "I did it all for you! I wanted to become your one and only girlfriend! I- I just wanted you to love me back!" I sniffled. "But clearly you never will… Just kill me! A horrible demon like me doesn't deserve to live in a world with someone as perfect as you! I just want to die! Please just end my suffering! Take me out of my misery, Senpai!" I pleaded, a sea of tears gushing out of my eyes.

Senpai seemed torn. He obviously didn't know what to do. Finally, a sly grin curved into his face. "How about this," Senpai announced. "I will forgive you under one condition."

"Please!" I begged. "Anything!"

"Good." He smirked. "Then kiss me."

My eyes widened. Tears stopped streaming down my face. "R- Really?"

Senpai answered me with a nod.

I leaned in, my heart about to explode. I had only dreamed of this moment. Finally, it happened. His soft, smooth lips collided with mine. He wrapped his arms around me and I could tell that my face was as a red as a tomato. We finally lifted our lips off of one another. I was just a part of the most spectacular moment in history. Replays of the kiss went on in my head countless times. My mind couldn't take it any longer. I swooned and fell onto the hard ground. I was unconscious.

* * *

I woke up, feeling the warmness of my covers surround me.

 _Was that just a dream?!_ I thought, praying that it was not. My heart finally stopped pounding like a drum when I saw a note on my nightstand.

" _Pleasant dreams, Ayano! Love, Taro."_ The note spelled.

I blushed and quickly got ready for school. _Today was going to be a great day!_ I decided.

* * *

I skipped out of my house, feeling the emotion 'joy' for the first time in my life. While my senpai had given me color, there will still plenty of emotions I still hadn't felt. I was relieved to finally not pretend to be normal, hiding the broken parts of me. Even though I had killed a few people, like that petty Osana, I finally felt normal. I made my way towards Senpai's house, humming with every step. Putting on my biggest, most lively smile, I knocked on Senpai's door, waiting to see his dreamy face in front of mine any second.

"Ugh, what do you want?" I heard. That was not the response I had expected. And why was there a petite girl with black hair and eyes as dark as coal standing at the door, rather than my Senpai?!

"Um, who are you?" I asked, trying to sound as polite as possible.

"Sakura Yamada," she groaned. "Just tell me, _what do you want_?!"

How could someone as… yuck… as her be related to Senpai? He was perfect in every way, while she was just… horrid!

"Uh, is Sen- I mean Taro here?" I questioned Sakura.

"Onii-Chan," she called to Senpai, using a tone that was the complete opposite of how she was speaking to me. "Some girl wants you. I wouldn't trust her, though. She looks homeless."

"Excuse me?!" I glared. "Homeless?!"

"I think she bites, too!" Sakura called out to Senpai again.

My hands balled up into fists, but I managed to take a deep breath. I couldn't kill this brat if Senpai was around!

Finally, Senpai arrived at the door.

"Oh, hello Ayano." He winked.

"Good morning Senpai!" I practically sang, making sure that the word 'Senpai' stuck out. Two could play at this game! My hatred instantly dissolved into thin air as Senpai grabbed my hand.

Sakura suspiciously studied us, noting that something was odd. Before I turned around to walk to school with Senpai, I saw a flicker of fire ignite in Sakura's dark eyes.

 _Do I have a new rival?_ I wondered, but only to have my thoughts interrupted by Senpai.

"What do you think of my sister?" Senpai asked me.

"Oh, she's… really something!" I replied, not wanted to lie to my senpai.

"Is that a good thing?" Senpai responded.

Biting my tongue, I managed to nod. I could have lied all day to everyone else, but it was a different story with Senpai. I didn't want to lose all of these colors in my dark, grey world if Senpai somehow found out the truth. I didn't want to lose the one thing that made me happy. He knew what I had done to a few... unfortunate students of Akademi High, so his trust in me meant more than ever before.


	2. Friends & Forgiveness

**CHAPTER TWO: Friends & Forgiveness**

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 _ **A/N: Here goes another chapter! Also, I can't believe that my first chapter had almost 100 different readers! That's amazing! Thank you so much! I hope you'll enjoy this chapter! Also, there are a few things you should probably know about this one. First of all, I mentioned the swim team captain. The name I used for her is not her official name, whatever it ends up being. I came up with her name, myself, so it's only headcanon. Also, I wrote that her family had debt problems due to Ronshaku Loans. Because I said that Kokona was killed by Saki during a murder-suicide in the previous chapter, I decided that the swim team captain would be the one to have the debt problems and be spared peacefully to avoid any conflicts, rather than Kokona. Anyways, enough with the Author's Note, let's get started! -wavesorcerer14**_

* * *

As Senpai and I continued our walk to school, I finally decided to ask him a question that I had been pondering about lately.

"Um, Senpai," I started, nervously biting my lip.

"Yes, Ayano?" Senpai replied.

"W-Why do you like me? After all that you've seen?" I questioned, just waiting to hear the cold, bitter words of 'I don't like you.'

Senpai stopped walking and thought for a moment. "Well, you… You proved that you deeply care about me. Yes, I know that I'm standing next to a murderer, but truth is, you've always caught my eye. Right from the start, I could tell that you were someone who didn't care about others' opinions. That takes guts, especially in this era. I know that you killed and tortured some of my closest friends, but when I actually think about it… I know that it was your way of proving your affection for me." I paused for a moment, tears welling in my eyes. "However, I still don't forgive you. Do you realize what you did to the families of your victims?!" More tears started streaming down my cheeks, but this time they were tears of regret. Sadness. Despair. "Saki-chan's parents were worried sick when you kidnapped her! After she murdered Kokona-chan because of your torturing and killed herself shortly after, her mother tried committing suicide! They were never the same because of you! I will only forgive you if you fix the damage you created."

Fighting through tears, I managed to splutter out, "How?! Also, you told me that you would forgive me for a kiss!"

"I was lying. The only way I will actually forgive you is so bring back peace to all of the families of your victims and restore back the positivity of Akademi High's atmosphere."

"How could I do that?" I cried.

"That's your problem, not mine," Senpai stated, only to walk away from me.

* * *

Head looking at my feet, I walked through the gates of Akademi High.

"Oh, hello Ayano." My gym teacher, Taiso-sensei, waved.

"...Hi…" I mumbled and walked towards the lockers.

I opened up my locker and took out my binder and some textbooks, preparing for class. Carrying my school materials, I headed towards Class 2-1 and dropped them off at my desk. Going back towards the fountain, I passed Midori Gurin, who was heading up to the roof. She was always very early for school, like me, and spent all of her free time on the roof, emailing some video game developer stupid questions. If she wasn't doing that, she was definitely bugging some other student with constant, annoying questions. Rumor has it that the game developer that she emails is the same one as Mai Waifu's overseas lover. Mai has always seemed angry and hostile towards Midori… But it doesn't matter. I have no time for silly gossip like that. I sprinted down the stairs before Midori could open her mouth and ran to the plaza.

"Hey, Yan-chan!" Yui Rio greeted me. She knew about my obsession with Senpai and was fine with it. One day, she saw me stab a student, but instead of screaming and running away, she complimented me on my kill. Normally, I would immediately go after any witnesses, but she was different. I felt a dark aura around her. While she refused to speak to me the day after, so no one would think she took part in my murder, we later became friends. I discovered that she tortures animals in her basement. She found out that I have been the serial killer at our school. We knew that we were going to be great friends right away.

I muttered some gibberish and sat down on one of the benches, right across from Musume Ronshaku. Sencho Suiei's (the swim team captain) elimination was one of the few times I gave mercy to a rival. Her family was in debt with a place called Ronshaku Loans. When I found out that Musume was the owner's daughter, I figured that I would have to blackmail him with Musume's life. He eventually agreed to my deal and he released all clients. However, when someone falls in love with my senpai, at least one person will get hurt. After I returned Musume in the instrument case when her father finally accepted my compromise, she always seemed paranoid, scarred for life. I enjoyed watching her. It made me feel so powerful that I ruined someone's life- who wasn't even one of my rivals!

"Ugh, what's wrong, Yan-chan?" Yui-chan curiously asked, knowing that I usually wasn't in a mood like this."

"Just leave me alone!" I practically yelled.

Taken aback, Yui-chan gave me a sympathetic glance, but reentered her circle of friends, knowing that if _I_ was in a mood like this, there would be nothing that _she_ could possibly do to help me, as I would've done it already.

Suddenly, I had an idea. I took out my phone and texted Info-chan: _Any ideas on how I can raise the school atmosphere and help all of my victims' families recover from their losses?_

Within a few seconds, Info-chan sent a reply: _I have a few suggestions. However, I need 20 panty shots first._

Grumbling about how stupid taking panty shots was, I checked my phone to see how many pictures I had already taken. 17. Crawling onto the floor, I pointed my phone up Mei Mio's skirt. _Snap_. One down, two to go. I moved over to Koharu Hinata. _Snap._ Finally, I went to Yuna Hina. _Snap._

"That's disgusting! Stop it, you creep!"

 _Huh?_ I looked up and saw Yuna staring at me, arms crossed. "Um… It's a misunderstanding! I was taking a picture of something else, I swear!" I pleaded, not wanted my reputation to lower.

"Oh, that makes perfect sense! ...I guess," Yuna responded, not entirely convinced, but still enough to not completely harm my reputation.

Either way, it didn't matter. I had my 20 panty shots and sent them all to Info-chan.

 _Perfect._ She texted back. _Here's what I'm thinking:_

* * *

 _ **A/N: Mua ha ha! I left you on a cliff hanger! Enjoy the suspense! -wavesorcerer14**_


	3. Schemes & Surprises

**A/N: First of all, thank you so much for your support! It makes me glad that I have some fans of this story! Anyways, I hope you enjoy this chapter. Oh yeah, and I decided that Yandere-chan's text messages will be in bold to avoid any confusion. Also, I'd just like to put out that this chapter will eventually have some VERY dark themes. I don't want to spoil anything for you guys, so if you feel like you can't handle those type of writings, you should leave immediately. Don't forget to comment! Enjoy! ~wavesorcerer14**

* * *

 _I'll start of with the school atmosphere ideas._ Info-chan texted. _You could get the school to have some type of festival. Knowing that their school's reputation is in danger, I bet that you could easily convince them to have it to ease everyone's minds. Just to let you know, I sell party supplies for pantyshots._ Groaning from that last comment, I continued reading her message. _Another idea is that you start some sort of fundraiser for all of your victims, such as a bakesale in their honor. Not only would people be glad to do something in honor of them, but who would believe that the sweet, innocent schoolgirl who started a bakesale in their names actually did the killing?_

 _ **I'll consider those ideas.**_ **I responded.** _ **Now what about the ideas on helping my rivals' families?**_

 _That will be 20 panty shots, please._

 _ **WHAT?! I already gave you 20 of them!**_

 _That was for the school atmosphere ideas._

 _ **You said that it was for both of them, you dirty liar!**_

 _No, I just wrote that I needed 20 panty shots. I never said anything about them being for the ideas. In fact, the ones you gave me were just for my previous services. The ideas I just gave you were free, as a result of my kindness._

 _ **Ugh, you stupid liar! Why do I even bother with you?**_

 _I never lied to you. I just didn't tell you the details. So do you want the ideas or not? I'm still waiting for my panty shots._

Knowing that I had no chance of winning this argument, I gave up. _**I'll focus on the school atmosphere plans at the time. I'll worry about Senpai's other requirements for his love another time.**_

 _Pleasure doing business with you, Ayano!_ Info-chan texted and I concealed my phone in my pocket.

Sighing, I headed towards class. Today was going to be a long day.

* * *

 _The world is lonely_

 _But my senpai lights it up_

 _Although he hates me_

I finished my haiku in my language class, feeling lonelier than ever. At least I had Yui-chan. _Oh yeah, I should probably talk to her!_ I thought. _Maybe I could come over to her house... Mine is too messy- and bloody- for her to see._

* * *

"Hey, Yui-chan, would you mind if I came over?" I asked during our lunch break, hoping that she would let me come to her house.

Clearly astonished by my question, as I was not the social type, despite us being friends, she answered, "Oh, uh, sure, Yan-chan. Is right after school okay? The Cooking Club isn't meeting today and I know that you aren't on a club. You should really join our club! It's so much fun, not to mention that we need more members because of your… deeds."

Pondering for a minute, I decided, "Maybe…"

Yui-chan seemed satisfied at that. Having nothing else to say, we started munching down our bentos. Yui-chan eventually opened her mouth, trying to break our silence, but the bell rang. Saved by the bell. I was not a fan of speaking to others about anything frivolous, particularly gossip. Unless it had to do with my rivals or Senpai, of course. Speaking of rivals, how was I to deal with Sakura? She isn't _that_ much of a threat currently, but I would rather eliminate her before things escalated to big trouble. I had no time to think about that, though. I had to rush to class.

* * *

The rest of the day seemed to go by in a flash. Class was boring- like always, and all I could think of was petting sessions with Senpai. While many would be in disbelief if they had found out, I actually had a very lewd mind. I could only imagine the _events_ leading up to the physical evidence of my love to Senpai. A baby, of course. _Sigh._ As of now, though, I could only dream of it, but the baby _will_ come into existence eventually. Mark my words. Anyways, since classes were over, it was time to meet Yui-chan.

"Hey Yan-chan!" Yui-chan nearly squealed when she saw me. "There's something I really want to show you at my house! I can't wait!"

"Uh... Cool." I blinked, wondering what she could possibly want me to see.

"Let's go!" Yui-chan grinned, and we headed towards her house.

* * *

"Here we are!" Yui-chan said once we arrived.

"You have a nice place, Yui-chan," I commented, sniffing the aroma of blood. That was unexpected, but not necessarily unwanted…

"Thanks! My parents are out on a business trip, just like yours, so I have the house place to myself! Anyways, I want to show you my basement! I think you'll like it!" Yui-chan cackled, as her face melted into a sly, wicked smile.

 _This will be interesting._ I decided.

After heading down a long and curvy staircase, we finally arrived at her surprise for me: Cages full of whimpering animals, mostly rabbits. One who would think that the sight of animal abuse would cause pleasure for me would be wrong. I felt absolutely nothing. Blood was splattered across dark, grey walls. Spiderwebs took up each corner of them. A few limp rabbit bodies were lying across the ground, all missing some features, such as whiskers, ears, and even eyes. A couple of dead puppies and kittens occupied the floor, too. A variety of bloody knives were resting on a table, which contained jars filled with body parts. No wonder Yui-chan was fine with my murders. She was a murderer, too! Still, I felt no remorse towards the animals. They were to die eventually, so why would that happening earlier make much of a difference?

"Hey Yan-chan, watch this!" Yui-chan guffawed.

Yui-chan picked up a bawling black bunny with eyes as dark as midnight. Just like my _senpai's_! The whimpering animal looked exactly like a bunny version of Senpai! Putting one arm around it, she picked up a knife with her free hand. Carving a large gash into the bunny's body, her pupils dilated, while the bunny shrieked in pain.

Yui-chan asked me, "Do you want to finish the honors?"

Using every bit of muscle in me to resist twitching, I managed to nod and took the knife from her now extended arm.

Looking back and forth from the crying bunny to the bloody knife in my hand, I realized I had an important decision to make. Holding my breath, I finally held up the knife.

"Go on," Yui-chan whispered, trying to hold in her excitement.

Bringing the knife down at the speed of light, I screamed, "I would never hurt Senpai!"

The knife went right into Yui-chan's stomach.


	4. Evidence & Evasion

**A/N: Welcome back to the next chapter! This is a mini-chapter, so don't worry that this is a LOT shorter than regular chapters. The next chapter will be a normal length. I just felt like this should be its own chapter. Also, the number for the police is different in Japan, not to mention that addresses are different. That's why they're like that in this story, in case you get confused. As always, don't forget to show your support towards this story! Anyways, on with the chapter! ~wavesorcerer14**

* * *

Yui-chan's blood splattered across the cold, stone-floored basement. Looking down at my hands, I noticed the red liquid streaming down, making large puddles of blood on the ground. Yui-chan's limp body was motionless, like an abandoned ragdoll. The bunny I had saved was staggering across the cellar, paws soaked with gore. I knew that Senpai loved animals, and prefered being surrounded by them outside, but why did I save this animal, especially when I would feel no sympathy towards it under any normal circumstances? The other animals didn't trigger any emotions similar to what this one had done. It beared a few similarities to Senpai, but it's not like it _was_ him. Either way, a had a lot of other problems to deal with first. Senpai would loathe me if he found out I murdered another person! The problem was, though, that I had nowhere to dispose Yui-chan's corpse. Even if I did, I couldn't just leave the animals here! They would problem starve to death! A week ago, I would've just left them here without any hesitation, but I had turned a new leaf. Attempted to, at least, with my only friend's dead body being evidence. If I couldn't dispose her body, what could I do? Suddenly, a lightbulb went on in my head. _I could make it look like it was a suicide!_ I realized. I could write a suicide note, expressing how "guilty" she felt about torturing animals! I did just have Language class earlier today, where I wrote a piece about my pain and sufferance!

 _The pain overwhelms me._

 _I can't take it any longer._

 _Too many innocent lives taken._

 _Too much agony in their lives._

 _The evidence surrounds me._

 _Alas, there is only one thing I can do:_

 _Goodbye world._

As I returned the pencil I borrowed from a drawer I had found, I decided this note was perfect. Placing the note near Yui-chan's corpse, I realized that there still was evidence that this "suicide" was a murder. The knife. I had to leave the knife in her, so my scheme wouldn't fail. I still had my fingerprints on it, though. Fingers crossed, I picked up Yui-chan's limp hand and smothered it all over the knife's handle, praying that all of my fingerprints would be covered by hers. Eventually satisfied, I returned her hand to its original position, and made my way upstairs. _Wait a minute!_ I remembered. _Her parents are on a business trip! No one will find her body!_ I had to take matters into my own hands. I picked up the nearest phone and dialled the police's number, 110.

"110, what's your emergency?" the receiver asked.

Using my best impression of Yui-chan, I said, "If you want my body, go to the seventh house on Block Thirteen."

"Excuse me?!" The receiver shouted, now alarmed.

I gave a bloodcurdling scream, as if I was just stabbed, and dropped the phone, which ended the call.

Picking up the phone, I dashed downstairs and quickly rubbed Yui-chan's hands against it, before leaving it next to her, in case the police decide to inspect it. Heart racing, I sprinted upstairs, out the door, and to my house, where I changed into non-bloody clothes. It was only a matter of minutes before Yui-chan's body was discovered.

* * *

 _The police arrive at the Rios' house._

 _The police discover the corpse of Yui Rio._

 _The police inspect the corpse of the girl who appears to have killed herself._

 _The police discover the suicide note._

 _The police discover the knife stained with the blood of Yui Rio._

 _The police fingerprints of Yui Rio on the knife._

 _The police believe that the incident was a suicide._

 _The case is closed._

 _The animals are all taken to the veterinary hospital._

 _The classmates of Yui Rio weep, but are also in disbelief of her now-known psychotic nature._

 _No one shows up at Yui Rio's funeral._


End file.
